CN201985158U

CN201985158U - LED chip with improved structure

Info

Publication number: CN201985158U
Application number: CN2011200769415U
Authority: CN
Inventors: 王维昀; 周爱新
Original assignee: FUDI ELECTRONIC MATERIAL Co Ltd DONGGUAN
Current assignee: FUDI ELECTRONIC MATERIAL Co Ltd DONGGUAN
Priority date: 2011-03-22
Filing date: 2011-03-22
Publication date: 2011-09-21
Anticipated expiration: 2021-03-22

Abstract

The utility model relates to an LED chip with an improved structure, which belongs to the technical field of LED preparation. The LED chip with the improved structure comprises a substrate, an N-type semi-conductor layer, an active layer and a P-type semi-conductor layer which are laminated from top to bottom sequentially, wherein a reflecting mirror is laminated below the substrate, granular silver particles are distributed between the reflecting mirror and the substrate, one side walls of the silver particles are adhered on the lower surface of the substrate, and the other side walls of the silver particles are bonded with the reflecting mirror. The silver particles positioned below the substrate are combined with the reflecting mirror to form a composite reflecting mirror; compared with a unitary metal reflecting mirror or a dielectric substance metal reflecting mirror, the composite reflecting mirror has high surface roughness, and the light rays emitted from the active layer can be changed from mirror refection into diffused reflection which can increase the light rays penetrating the light output surface of the LED chip; therefore, by using the LED chip, the light output efficiency can be effectively improved, and the lighting brightness can be finally improved.

Description

A kind of structure improved led chip

Technical field

The utility model relates to the LED preparing technical field, relates in particular to a kind of structure improved led chip.

Background technology

Cause the whole world to face the threat of energy shortage and earth environment great change because of excessively developing, the novel and light source energy-saving and carbon-saving notion becomes one of 21st century illumination most important.Light-emitting diode (Light Emitting Diode---the LED) representative of the green illumination light source of beyond doubt tool potentiality to be exploited; Advantages such as light-emitting diode has that volume is little, caloric value is low, power consumption is little, the life-span is long, reaction speed is fast, environmental protection and high brightness.Rely on above-mentioned many-sided advantage, light-emitting diode is used more and more general and range of application diversification day by day, as traffic lights, automobile-used lighting apparatus, outdoor display, LCD TV and mobile phone backlight etc.

Along with the led chip technology of preparing constantly improves, how to improve brightness and become the important indicator that LED enters lighting field, wherein can not be ignored especially with gallium nitride (GaN) series LED institute role.Though existing LED lamp can be realized illumination functions to a certain extent, the ubiquity light extraction efficiency is not high, and defectives such as further raising are demanded in brightness urgently.

Summary of the invention

The purpose of this utility model is to provide a kind of light extraction efficiency, brightness all higher structure improved led chip at the deficiencies in the prior art.

For achieving the above object, the utility model is achieved through the following technical solutions.

A kind of structure improved led chip, include the substrate, n type semiconductor layer, active layer and the p type semiconductor layer that are cascading from bottom to up, the stacked speculum that is provided with in the below of described substrate, be distributed with granular silver particles between speculum and the substrate, one sidewall of silver particles adheres to the lower surface of substrate, and all the other sidewalls of silver particles and speculum are fitted.

Wherein, described silver particles is hemispherical, and the spherical of silver particles and described speculum are fitted, and the horizontal plane of silver particles adheres to the lower surface of described substrate.

Wherein, described n type semiconductor layer is a N type GaN layer, and described active layer is the multiple quantum trap luminous layer of InGaN/GaN, and described p type semiconductor layer is a P type GaN layer.

Wherein, described substrate is a silicon carbide substrate.

Wherein, described substrate is a sapphire substrate.

Wherein, described n type semiconductor layer is electrically connected with N type welded gasket, and described p type semiconductor layer is electrically connected with P type welded gasket.

Wherein, be provided with transparency conducting layer between described P type welded gasket and the described p type semiconductor layer, P type welded gasket, transparency conducting layer and p type semiconductor layer are electrically connected successively.

Wherein, described transparency conducting layer is indium oxide gallium transparency conducting layer or ZnO transparent conductive layer.

Wherein, described speculum is TiO ₂/ SiO ₂Speculum.

The beneficial effects of the utility model are: a kind of structure improved led chip described in the utility model, include the substrate, n type semiconductor layer, active layer and the p type semiconductor layer that are cascading from bottom to up, the stacked speculum that is provided with in the below of described substrate, be distributed with granular silver particles between speculum and the substrate, one sidewall of silver particles adheres to the lower surface of substrate, and all the other sidewalls of silver particles and speculum are fitted.The silver particles and the reflector group that are positioned at the substrate below merge the formation composite reflector, for single metallic mirror or dielectric medium speculum, this composite reflector has higher surface roughness and the light that active layer can be sent becomes the diffuse reflection state by the direct reflection state, and diffuse reflection can increase the light that appears exiting surface of the present utility model; So the utility model can improve light extraction efficiency and the final brightness of illumination that promotes effectively.

Description of drawings

Utilize accompanying drawing to come the utility model is further described below, but any restriction of the present utility model in pairs inadequately of the embodiment in the accompanying drawing.

Fig. 1 is the structural representation of a kind of structure improved led chip of the utility model.

In Fig. 1, include:

1---substrate 2---n type semiconductor layer 3---active layer

4---p type semiconductor layer 5---speculum 6---silver particles

7---N type welded gasket 8---P type welded gasket 9---transparency conducting layers.

Embodiment

For quote and know for the purpose of, hereinafter employed technical term, write a Chinese character in simplified form or abridge and be summarized as follows:

GaN---gallium nitride; InGaN/GaN---indium gallium nitride/gallium nitride; TiO ₂---titanium dioxide; SiO ₂---silicon dioxide.

Come the technical solution of the utility model is known intactly description that obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment below in conjunction with embodiment.Based on embodiment of the present utility model, the every other embodiment that those of ordinary skills are obtained under the prerequisite of not making creative work belongs to the scope that the utility model is protected.

As shown in Figure 1, a kind of structure improved led chip, include the substrate 1, n type semiconductor layer 2, active layer 3 and the p type semiconductor layer 4 that are cascading from bottom to up, the stacked speculum 5 that is provided with in the below of described substrate 1, be distributed with granular silver particles 6 between speculum 5 and the substrate 1, one sidewall of silver particles 6 adheres to the lower surface of substrate 1, and all the other sidewalls of silver particles 6 and speculum 5 are fitted.

In the utility model preparation process, at first use evaporator to plate layer of even silver film at the lower surface of substrate 1; Substrate 1 after evaporation finished is put into quick anneal oven and is carried out annealing in process, wherein, the purpose of annealing in process is: make silver-colored film melted by heat and reach molten condition, silver-colored liquation flocks together owing to the Van der Waals force effect between the silver-colored molecule and finally makes the silver-colored film of stratiform become granular silver particles 6; Treat after the silver-colored film particlesization; cooled and solidified also utilizes evaporator to plate the speculum 5 that one deck is used for reflection ray again below substrate 1; at this moment; silver particles 6 is held between substrate 1 and the speculum 5; wherein; one sidewall of silver particles 6 adheres to the lower surface of substrate 1, and all the other sidewalls of silver particles 6 and speculum 5 are fitted.

When the utility model connects forward voltage, at this moment, p type semiconductor layer 4 is connected with the positive pole of external power supply, n type semiconductor layer 2 is connected with the negative pole of external power supply, the hole that is positioned at p type semiconductor layer 4 under electric field action towards n type semiconductor layer 2 one side shiftings, towards p type semiconductor layer 4 one side shiftings, hole and electronics are compound and produce the fluorescence of spontaneous radiation at active layer 3 under electric field action for the electronics that is positioned at n type semiconductor layer 2.The silver particles 6 that is positioned at substrate 1 below is with speculum 5 combinations and form composite reflector, the light that sends by active layer 3 after silver particles 6 and speculum 5 reflections again the exiting surface through being positioned at p type semiconductor layer 4 one sides be transmitted through the external world; For existing single metallic mirror or dielectric medium speculum, this composite reflector has higher surface roughness and the light that active layer 3 can be sent becomes the diffuse reflection state by the direct reflection state, for direct reflection, diffuse reflection can increase the light that appears exiting surface; So the utility model can improve light extraction efficiency and the final brightness of illumination that promotes effectively.In addition, speculum 5 of the present utility model can be TiO ₂/ SiO ₂Speculum, wherein, this TiO ₂/ SiO ₂Speculum comprises the TiO that stacks gradually and be crisscross arranged ₂Layer and SiO ₂Layer, the utility model is by adopting TiO ₂Layer and SiO ₂The version that layer piles up realizes the effect of comprehensive reflection, and then further reduces light loss and improve light extraction efficiency; Certainly, speculum 5 of the present utility model also can be the speculum of other types, for example metallic mirror that is prepared from by metal materials such as gold, aluminium, nickel or chromium.

In addition, in the silver-colored film annealing process of stratiform, the silver liquation is gathered into bulk and finally becomes silver particles 6 through cooled and solidified owing to intermolecular Van der Waals force effect, silver particles 6 after the moulding generally is hemispherical, at this moment, the spherical of silver particles 6 and speculum 5 are fitted, and the horizontal plane of silver particles 6 adheres to the lower surface of substrate 1.Certainly, above-mentioned silver particles 6 shapes do not constitute restriction of the present utility model, and in concrete preparation forming process, silver particles 6 can also be prepared into other shapes.

The utility model can be applied to various types of light-emitting diodes and be not limited only to the light-emitting diode of a certain particular type, and promptly the utility model can be applied in the dissimilar light-emitting diode such as GaN series LED, GaAs series LED, gallium chloride series LED; Wherein, consider GaN series LED, so the utility model is applied to the effect that GaN series LED will be obtained highly significant in the important function that lighting field played.When the utility model was applied to GaN series LED, at this moment, n type semiconductor layer 2 was a N type GaN layer, and active layer 3 is the multiple quantum trap luminous layer of InGaN/GaN, and p type semiconductor layer 4 is a P type GaN layer.

Further, substrate 1 can be silicon carbide substrate, also can be sapphire substrate.Wherein, silicon carbide substrate has favorable conductive and heat conductivility, and this helps the utility model is applied in the bigger high-power LED chip of area; Sapphire substrate have stability better, mechanical strength is higher and characteristics such as processing technology maturation, this helps popularization of the present utility model and application.

Further, the substrate 1 of considering unlike material has different electric conductivities, when substrate 1 is sapphire substrate, because sapphire substrate can not conduct electricity, can not make vertical stratification so make the led chip of substrate 1 by sapphire substrate, can only make horizontal structure as shown in Figure 1, at this moment, n type semiconductor layer 2 is electrically connected with N type welded gasket 7, p type semiconductor layer 4 is electrically connected with P type welded gasket 8, N type welded gasket 7 is connected with the negative pole of external power supply, and P type welded gasket 8 is connected with the positive pole of external power supply; When substrate 1 was silicon carbide substrate, because silicon carbide substrate has excellent conductive performance, so the led chip of making substrate 1 by silicon carbide substrate can be made vertical stratification, at this moment, N type welded gasket 7 was vertically arranged with P type welded gasket 8.

As preferred embodiment, be provided with transparency conducting layer 9 between described P type welded gasket 8 and the described p type semiconductor layer 4, P type welded gasket 8, transparency conducting layer 9 and p type semiconductor layer 4 are electrically connected successively.In the utility model course of work, transparency conducting layer 9 makes electric current dispersedly by P type GaN layer and the multiple quantum trap luminous layer of InGaN/GaN, has so just increased the light-emitting area of the multiple quantum trap luminous layer of InGaN/GaN and then has increased brightness of the present utility model.In the utility model preparation process, transparency conducting layer 9 is covered on the top of P type GaN layer, and P type welded gasket 8 is connected together P type GaN layer and external power supply.In addition, the transparency conducting layer 9 that the utility model adopted can be indium oxide gallium (ITO) transparency conducting layer, also can be the ZnO transparent conductive layer, certainly, above-mentioned transparency conducting layer 9 does not constitute restriction of the present utility model, the transparency conducting layer that the utility model adopted can also be thin metal type transparency conducting layer, for example nickel-Jin double-metal layer.

Above content only is preferred embodiment of the present utility model, for those of ordinary skill in the art, according to thought of the present utility model, the part that all can change in specific embodiments and applications, this description should not be construed as restriction of the present utility model.

Claims

1. structure improved led chip, include the substrate (1), n type semiconductor layer (2), active layer (3) and the p type semiconductor layer (4) that are cascading from bottom to up, it is characterized in that: the stacked speculum (5) that is provided with in the below of described substrate (1), be distributed with granular silver particles (6) between speculum (5) and the substrate (1), one sidewall of silver particles (6) adheres to the lower surface of substrate (1), and all the other sidewalls of silver particles (6) and speculum (5) are fitted.

2. a kind of structure improved led chip according to claim 1, it is characterized in that: described silver particles (6) is hemispherical, the spherical of silver particles (6) and described speculum (5) are fitted, and the horizontal plane of silver particles (6) adheres to the lower surface of described substrate (1).

3. a kind of structure improved led chip according to claim 1, it is characterized in that: described n type semiconductor layer (2) is a N type GaN layer, described active layer (3) is the multiple quantum trap luminous layer of InGaN/GaN, and described p type semiconductor layer (4) is a P type GaN layer.

4. a kind of structure improved led chip according to claim 3 is characterized in that: described substrate (1) is a silicon carbide substrate.

5. a kind of structure improved led chip according to claim 3 is characterized in that: described substrate (1) is a sapphire substrate.

6. a kind of structure improved led chip according to claim 5 is characterized in that: described n type semiconductor layer (2) is electrically connected with N type welded gasket (7), and described p type semiconductor layer (4) is electrically connected with P type welded gasket (8).

7. a kind of structure improved led chip according to claim 6, it is characterized in that: be provided with transparency conducting layer (9) between described P type welded gasket (8) and the described p type semiconductor layer (4), P type welded gasket (8), transparency conducting layer (9) and p type semiconductor layer (4) are electrically connected successively.

8. a kind of structure improved led chip according to claim 7 is characterized in that: described transparency conducting layer (9) is indium oxide gallium transparency conducting layer or ZnO transparent conductive layer.

9. a kind of structure improved led chip according to claim 1 is characterized in that: described speculum (5) is TiO ₂/ SiO ₂Speculum.